The present invention relates to a microprocessor and, more particularly, to a micro-processing control device of a motor.
Along with progress of high scientific technology, the development of many electronic products tends to multi-functionality and miniaturization. Therefore, for many motor-driven electronic products like recorders, compact disk players, and digital still cameras, the miniaturization and multi-functionality of the motor control device and driver have become important issues in motor design.
In the control device of a common motor, in consideration of the requirements of forward rotation, reverse rotation, and braking of the motor, three signal input pins are required in an IC chip to provide signals for forward rotation, reverse rotation, and braking, respectively. With also a power input, a ground, a positive electrode and a negative electrode of the motor, and control signals, the whole motor control circuit at least requires eight pins in the IC chip so that the volume of the manufactured IC chip will be too large and cannot meet the requirement of miniaturized electronic products. Besides, in order that the rotation speed of an operating motor can be detected and adjusted, the control device is usually electrically connected to a Hall effect device. In addition to the design of the above signal control device and the Hall effect device, it is also necessary to arrange a drive current switch like a MOSFET in the motor to provide a power source for the motor. Because the components are complicated and the MOSFET is bulkier, the above conventional design cannot apply to drive and control components of motor in common miniaturized products, i.e., the practical value is low.
Accordingly, the present invention aims to propose a motor control device having a small volume and multiple functions.
The primary object of the present invention is to propose a motor control device, which uses the same pin as an input contact of rotation direction and braking signals of a motor to have the advantages of reduced number of pins and shrunk volume of the motor control device.
Another object of the present invention is to propose a motor control device, which has a small volume, a simple architecture, and can adjust and control the rotation speed of a motor.
According to the present invention, a motor control device comprises a signal control circuit having an input pin to output different motor drive signals according to the input electronic signals. The signal control circuit is electrically connected to an over current protection circuit and an over voltage protection circuit. Two switch circuits of brake before make configuration are connected to the signal control circuit. An inverter is arranged between the two switch circuits. The inverter switches the motor drive signal among the two switch circuits and transmits it to a driver, which is connected to a motor drive circuit. A power source circuit is connected to the motor drive circuit to provide electricity for the motor drive circuit. A back electromotive force (back EMF) component for detection and control of the rotation speed of motor is disposed in the driver.